Tim Floyd warned everyone about games like this. He repeated that the Trojans were young, that their bevy of preseason injuries could lead to sloppy play early in the season. Guys would be behind in adjusting to college ball, he reasoned. Their stamina and knowledge would be limited.

Thursday in the Galen Center against Oklahoma, that USC team showed up - at least on the offensive end - for the first 30 minutes. But that Davon Jefferson did not.

The 21-year-old freshman forward out of Lynwood missed a bulk of preseason workouts with a knee injury. He did not even play in the first three games, because he was not up to speed with the Trojans' schemes, Floyd said.

Against the Sooners, Jefferson followed a standout performance in the Anaheim Classic championship, with 23 points and nine rebounds - both team highs that kept USC afloat until O.J. Mayo broke out of a slumber midway through the second half, to lead the Trojans to a 66-55 victory.

"I think both (Jefferson) and Taj (Gibson) are difficult matchups, because they both can put the ball on the floor; and they both face and shoot from 15 feet; and they can go to the post," Floyd said. "They're both pretty good offensive rebounders."

But with Gibson a non-factor because of foul trouble, those responsibilities fell almost solely to Jefferson. Four of his rebounds were offensive, and he scored on consecutive putbacks in the first half, off Mayo misses.

Jefferson shot 7-of-9 from the field and 9-of-11 from the foul line.

Asked if there is anything he can do now that he couldn't have done the first three games, Jefferson said, "Not really. I just know I can contribute to the team a lot. And when Coach put me in there, that's what I tried to do."

USC sank only a third of its shots in the first half but was 13-of-22 (59.1 percent) from the floor during the final 20 minutes. The Trojans also made 18-of-25 free throws, while limiting Oklahoma to only 11 shots from the foul line.

"We're making more free throws than the other team is attempting, night in and night out, which is a huge stat for us," Floyd said. "We're a growing offensive team. We've spent a lot of time on the defensive end."

The Sooners' leading scorers are forward Blake Griffin and center Longar Longar, both averaging double digits. But USC held them to seven combined points.

Through the ugly first half - and the game - the Trojans managed to deny the ball to Oklahoma's post players, forcing the Sooners to hock up outside shots.

The Trojans also grabbed more rebounds (38-28) against a bigger team.

"We understand they have a terrific front line in Griffin and Longar and (Keith) Clark," Mayo said. "We just wanted to shut down the lane."

As USC did that, Oklahoma managed to shut down Mayo through the first half, holding him to two points on 1-of-8 shooting. But the freshman sensation erupted with 8:19 remaining in the game, and USC up only six points.

With smooth jumpers, slicing penetration and a three-pointer mixed in, Mayo led the Trojans on an 11-3 run, in which he scored all but one USC basket. He scored 13 of his 18 points in those final nine minutes.

As usual, Mayo credited his teammates, saying they set good screens for him. In the second half, Floyd said he called for more offensive formations that sent four players to the baseline and left Mayo on his own, with the ball in his hands.

The freshman said he and the team were not frustrated at halftime, when, despite holding an 11-point advantage, they had scored only 29 points.

"I think that's a good situation for us," said Mayo, in a nod to the defense.

Perhaps more noteworthy than the play of the defense, Jefferson or Mayo, is that fact that Gibson played only nine minutes because of foul trouble. Floyd will not easily forget how last season's team fell apart in the Sweet Sixteen against North Carolina, blowing a huge lead when its center went to the bench.

Gibson scored two points, grabbed three rebounds and committed five fouls.

"It looked like we may have made strides from a year ago, just from the standpoint of we couldn't play without Taj in the lineup last year," Floyd said. "We saw that in the Carolina game.

"We were able to play through that tonight against a quality front line."

NOTED: Sophomore guard Daniel Hackett received a kick to the calf, and freshman guard Angelo Johnson was part of a knee-on-knee collision. Both are expected to return for Kansas on Sunday, although Floyd said they were not feeling great after Thursday's game. Keyshawn Johnson was courtside, and MLB Hall of Fame first baseman Eddie Murray also was in attendence. Former point guard Brandon Granville (1998-2002) was honored at halftime with a school jacket.